Figure 2.

Epithelium denudation and KCl-induced isometric force in tracheal rings from Cav-1 KO and wild-type mice. The epithelium of excised tracheal segments was removed by threading with surgical silk then rolling the rings for 3 revolutions on a wetted paper towel. (A) Masson's trichrome staining of randomly selected tracheal preparations showing result of epithelial (Epi) denudation. Tracheal specimens from Cav-1 KO mice are shown. (B) Isometric methacholine concentration-response studies were performed using epithelium-denuded tracheal segments from Cav-1 KO (9 rings from 6 mice) and wild-type (9–12 rings from 5–7 animals) mice. After equilibration, rings were incubated for 30 min with either vehicle or indomethacin (INDO), then isometric force was measured with increasing concentrations of methacholine (10⁻⁹–10⁻³ M). Results shown are the mean ± SEM, indomethacin had minimal effects on responsiveness to methacholine (one-way anova, P > 0.05). (C) Receptor-independent force generating capacity of tracheal rings with (+) and without (−) epithelium (Epi) from wild-type and Cav-1 KO mice was assessed based on isometric force measured after 63 mM KCl substituted with K-H solution treatment. For each group, two to three tracheal rings from at least three to four mice were studied. There were no significant differences between the groups (one-way anova, P > 0.05). (D) Histogram comparing basal tone in tracheal rings from Cav-1 KO and wild-type mice with (+) and without (−) epithelium. For each group, five to seven tracheal rings from at least three to four mice were studied. There were no significant differences between the groups (one-way anova, P > 0.05). ns, not significant.